New Jersey State Police said the mother of the child and another individual were taken to hospitals for medical care.

New Jersey State Police Sgt. Brian Polite identified the woman flown to Morristown Medical Center as 28-year-old Melissa Nemeth, who was living in an apartment in the building at 571 Route 46.

Polite said 20-year-old Joshua Weaver, of Bangor, was taken to Hackettstown Regional Medical Center. It wasn't clear why he was at the scene of the fire. Both Weaver and Nemeth suffered smoke inhalation, Polite said, and neither injury appeared life-threatening.

But it wasn't until the fire was extinguished, police say, that crews were able to enter the home for an in-depth search. Once they were able to do so, police say, they found and identified a 2-year-old boy who had perished in the blaze. The child's name wasn't released Tuesday. State police in Washington indicated that two troopers involved in the rescue effort had to be treated for smoke inhalation, but Polite said only one trooper was taken to Warren Hospital for treatment.

Route 46 was closed about a mile in both directions for about three hours. When authorities began allowing westbound traffic through after 4 p.m., firefighters could be seen in front of the home holding up a large, blue tarp. Several people unassociated with the emergency response could be seen crowded near an ambulance parked along the road.

Ferguson said the investigation into how the fire began likely will be a slow-moving process.

"We're out on it, but they'll need to take their time investigating it," Ferguson said.

Property records indicate the residence is owned by Thomas and Anne Washburn, of Harmony Township.

Anne Washburn confirmed Tuesday night that she and her husband rent out the property, but she declined to say to whom and for how long the current occupants have lived there. Washburn said she was informed about the fire.

Warren County Fire Marshal Joe Lake referred all inquires to New Jersey State Police, who he said are in charge of the investigation.

Prior to that fire, an arson on June 2, 2009, in Mansfield Township claimed the life of 96-year-old Carl Salerno and 89-year-old Margaret Salerno and badly injured their son Anthony P. Salerno, then 54.